Listen

Instagram

Updated at 7:05 p.m. ET

Facebook said on Tuesday it will ban anti-vaccination ads, following widespread pressure on the social network to curb harmful content.

Under the new global policy, the company will no longer accept ads discouraging people from getting vaccines; ads that portray vaccines as unsafe or ineffective; or ads claiming the diseases vaccines prevent are harmless.

Russia's trolling specialists have evolved their disinformation and agitation techniques to become subtler and tougher to track, according to new research unveiled on Thursday.

A cache of Instagram posts captured by researchers showed that the Russians were "better at impersonating candidates" and that influence-mongers "have moved away from creating their own fake advocacy groups to mimicking and appropriating the names of actual American groups," wrote Young Mie Kim, a University of Wisconsin professor who analyzed the material with her team.

A Chillicothe teen's challenge of how social media treats body image is getting worldwide media attention.